Contents

Benefits of Asd

Running this daemon is beneficial for two reasons:

Reduced wear to physical discs

Speed

Since the target directories are relocated into tmpfs, the corresponding onslaught of I/O associated with system usage of them is also redirected from the physical disc to RAM, thus reducing wear to the physical disc and also improving speed and responsiveness. The access time of RAM is on the order of nanoseconds while the access time of physical discs is on the order of milliseconds. This is a difference of six orders of magnitude or 1,000,000 times faster.

Setup and Installation

Edit /etc/asd.conf

Edit the included /etc/asd.conf defining the target directories in the WHATTOSYNC array. These will be syncronized and managed by asd.

Note: At least one location needs to be defined.

Example:

WHATTOSYNC=('/var/log' '/srv/http' '/home/foo/bar')

Optionally redefine the location of the tmpfs space to use. Do this in the TMPFS variable. Note that for Arch Linux, the default value of /dev/shm should work just fine. Be sure to read the warning about using software such as bleachbit with asd since bleachbit likes to remove files stored in /tmp. This is why a value of /dev/shm is better.

Using asd

The initial synchronization will occur when the daemon starts. Additionally, cron (if running) will call it to sync or update once per hour. Finally, asd will sync back a final time when it is called to stop.

Using SysVinit (Arch default)

Call the daemon to start, stop, or sync (restart) like any standard Arch daemon:

# rc.d command asd

It is highly recommended to start/stop the daemon at boot/shutdown. This is accomplished by adding asd to the DAEMONS array in /etc/rc.conf like so:

DAEMONS=(... @asd ...)

Using systemd

Users making use of Systemd may manage the service using the systemctl command. Start/stop the service using: